A student from Leicestershire wrote: “People had to leave the hall in many of the exams as they were having panic attacks and crying, and many people were having nosebleeds from all the stress.”

A pupil from Kent said: “A ridiculous amount of people having panic attacks before/during exam.”

Another from Essex wrote: “These exams have been too stressful and adults do not understand the pressures they have placed on us.”

One pupil reported that someone tried to kill themself: “Some people have been crying at home or just stressing to the point of not eating or sleeping properly, but I’ve witnessed the worst way it can affect us. My best friend, a capable and smart friend with predicted grades of 7s, attempted suicide due to the pressures of the approaching exams.

“Though they survived, they will have lasting damage, physical and mental. They completed their exams like a ghost, drifting through and just trying to reach the end. For the months of May and June, we do not feel human any more.”

The revamped GCSEs are designed to be more rigorous, with expanded content, and they are assessed almost exclusively by end-of-course exams, rather than coursework or modular tests.

“Dearest Michael Gove,” said one candidate, “if I can thank you for one thing, it would be that you have brought me closer to other struggling students across the nation, who are also facing the worst mental health problems teenagers have ever experienced.

“We come together to celebrate the end of an absolutely treacherous era, all thanks to you. I look forward to results day to see how shockingly bad these mental health problems caused by the new system have affected my grade. No coursework, no second chance.”

Pupils said they were exhausted after sitting between 20 and 30 exams, sometimes two a day. They said they felt underprepared, the new content was introduced in a hurry with inadequate resources, and their teachers struggled to cover the expanded courses.

A pupil from Birmingham said: “I was exhausted from doing back-to-back exams and found that after each exam, my self-esteem and motivation really deteriorated due to how hard I found them.

“The new GCSE system means I only get one chance to prove my worth for my subjects. My entire two years of learning content is all assessed within no less than one hour.”

One London student complained of having two exams a day on five days within two weeks. “I have burst into tears multiple times on public transport after finishing an exam, and I have seen this to be the case with lots of my peers as well,” they said.

Geoff Barton, the general secretary of the Association of School and College Leaders, said: “Unfortunately, this [getting through exam season] has not been without considerable cost in terms of stress and anxiety, and we are extremely concerned about the impact on the wellbeing of pupils.

“The new exams are harder and students taking GCSEs have had to sit more papers, memorising vast amounts of information and regurgitating facts in an intense six-week period, and under the weight of expectations generated by a high-stakes system.

“We are particularly concerned about the impact on less able students, who may have felt especially demoralised by the demands of these exams.”

Barton reassured students they would not be disadvantaged by being the first cohort to sit the new GCSEs. The exams regulator, Ofqual, uses a technique called comparable outcomes, which ties grades to the cohort’s prior attainment, so results this year will be similar at a national level to previous years.

“In the longer term, we need to ask ourselves some searching questions as a society about whether the perceived benefits of a more rigorous exam system are outweighed by the toll on the mental health of our young people,” he said.

An English teacher in London said the exams were inaccessible for less able pupils. “My students are so frustrated with the difficulty of the texts that they have to read in the exam; this proves to be a huge barrier when answering the questions. On more than one occasion, children have asked me: ‘Do they want us to fail?’ I am so sad for them,” they said.

A private tutor in Lincoln said many parents had sought extra tuition for children struggling with GCSEs: “This exam season, everyone has been feeling under pressure, stressed and mentally exhausted. These are not suitable exam conditions.

“How are students meant to learn, and learn well, when they are under so much pressure? It leads to the question of what are we really testing – knowledge, or ability to survive in harsh conditions?”

A pupil from Manchester accused the government of trying to “pump out A* machines” at the expense of nurturing creativity.

However, another student from Manchester praised the tougher exams. “I believe that doing these exams builds up work ethic and resilience, something that is lacking in this generation,” they said. And a pupil from Reading said: “I do feel that the change is for the better, however, I think that the process was very rushed.”

A parent from the Isle of Wight wrote: “My eldest child has just completed his GCSEs and has found the whole process incredibly stressful. The pressure has led him to fall apart on a number of occasions. He has been sick with worry and struggled to sleep.

“The current system seems to be all about the performance of the schools and very little to do with individual children or their wellbeing. At what point will people recognise that not everyone is academically gifted?”

A Department for Education spokesperson said: “We know that exam season can be a time of heightened emotions for pupils who want to do their best. But while testing has always been an important part of education, it should never be at the expense of a young person’s wellbeing.

“We trust schools to make sure that pupils preparing for exams get the help and support that they need, when they need it, working with parents to do this.”

•In the UK, Samaritans can be contacted on 116 123 or emailjo@samaritans.org. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international suicide helplines can be found at www.befrienders.org.